Mitigation of Parasitic Reflections over Periodic Surface Impedance Modulated Panels

This communication addresses the issue of parasitic reflections from reflecting panels using Surface Impedance Modulation (SIM). These reflections are due to Floquet harmonics appearing because of the SIM periodicity. Different SIM panels made of microstrip dipoles are compared at f=8GHz using ANSYS® HFSS®. New metrics are proposed to assess the dipole performance with regards to Harmonic Lobe levels (HLL). Design rules are derived, which permit to mitigate higher order harmonics in unwanted directions.